Those who do not talk about traumatic experiences may fare better than those who "let it all out", according to researchers. A study compared the progress of 3,000 people who took different approaches over two years following the 9/11 attacks. It found that people initially unwilling to talk were less likely to be adversely affected two years later.
Other psychologists, however, have pointed out that other studies have suggested that for many people, talking does help.
The popular advice that it is better to talk about your feelings after a trauma has been the subject of many research projects.
Professor Stephen Joseph, who specializes in trauma following disasters, says that it is important not to generalize about the "right" approach for all patients.